Nursing Elites

1. Which of the following valves prevents backflow of blood from the right ventricle into the right atrium of the heart?

• A. Aortic
• B. Tricuspid valve
• C. Pulmonic
• D. Mitral valve

Correct answer: B

Rationale: The correct answer is the tricuspid valve. The tricuspid valve is located between the right atrium and the right ventricle of the heart. Its main function is to prevent the backflow of blood from the right ventricle into the right atrium during the heart's pumping cycle. Choice A, the aortic valve, is responsible for preventing backflow from the aorta into the left ventricle. Choice C, the pulmonic valve, prevents backflow from the pulmonary artery into the right ventricle. Choice D, the mitral valve, prevents backflow from the left ventricle into the left atrium.

2. Which of the following illustrates a positive feedback mechanism?

• A. Maintaining blood pressure
• B. Uterine contractions during childbirth
• C. Body temperature control
• D. Control of blood sugar

Correct answer: B

Rationale: The correct answer is uterine contractions during childbirth. This is an example of a positive feedback mechanism where the initial stimulus (contractions) leads to an increase in intensity and frequency, ultimately resulting in childbirth. In contrast, choices A, C, and D (maintaining blood pressure, body temperature control, and control of blood sugar) are examples of negative feedback mechanisms. These mechanisms work to maintain stability by counteracting any deviations from the set point, rather than amplifying the response like in a positive feedback mechanism.

3. Which of the following processes is most important for the continuation of the human species?

• A. Responsiveness
• B. Movement
• C. Reproduction
• D. Respiration

Correct answer: C

Rationale: Reproduction is the most important process for the continuation of the human species as it involves the creation of new individuals. Without reproduction, the human species would cease to exist. Responsiveness and movement are essential for individual survival and functioning but do not directly impact the continuation of the species. Respiration is crucial for obtaining energy but is not directly linked to the continuation of the species.

4. Which of the following is not true of organelles?

• A. They carry out specific activities.
• B. They are only present in human cells.
• C. They are composed of aggregates of large molecules.
• D. They are found in many types of cells.

Correct answer: B

Rationale: Organelles are not exclusive to human cells but are present in various types of cells across different organisms. Option B is incorrect as it suggests that organelles are only found in human cells, which is false. Choices A, C, and D are correct statements about organelles. Organelles indeed carry out specific activities, are made up of aggregates of large molecules, and can be found in many types of cells.

5. An investigator who conducts an experiment to determine how temperature changes affect the rate at which the heart beats is most likely a(n)

• A. anatomist.
• B. physiologist.
• C. chemist.
• D. biochemist.

Correct answer: B

Rationale: The correct answer is 'physiologist.' A physiologist studies how the body functions under normal and abnormal conditions, including how temperature changes can affect physiological processes like heart rate. An anatomist focuses on the structure of organisms rather than their functions, making choice A incorrect. Choices C and D are also incorrect as they are more related to the study of chemicals and biochemistry, which are not directly relevant to investigating the effects of temperature on heart rate.

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